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//===-- LiveRangeInfo.h - Track all LiveRanges for a Function ----*- C++ -*-==//
//
// This file contains the class LiveRangeInfo which constructs and keeps
// the LiveRangMap which contains all the live ranges used in a method.
//
// Assumptions:
//
// All variables (llvm Values) are defined before they are used. However, a
// constant may not be defined in the machine instruction stream if it can be
// used as an immediate value within a machine instruction. However, register
// allocation does not have to worry about immediate constants since they
// do not require registers.
//
// Since an llvm Value has a list of uses associated, it is sufficient to
// record only the defs in a Live Range.
//
//===----------------------------------------------------------------------===//
#ifndef LIVE_RANGE_INFO_H
#define LIVE_RANGE_INFO_H
#include "Support/HashExtras.h"
#include "llvm/Analysis/LiveVar/ValueSet.h"
class LiveRange;
class MachineInstr;
class RegClass;
class MachineRegInfo;
class TargetMachine;
class Value;
class Function;
class Instruction;
typedef std::hash_map<const Value*, LiveRange*> LiveRangeMapType;
typedef std::vector<const MachineInstr*> CallRetInstrListType;
//----------------------------------------------------------------------------
// Class LiveRangeInfo
//
// Constructs and keeps the LiveRangMap which contains all the live
// ranges used in a method. Also contain methods to coalesce live ranges.
//----------------------------------------------------------------------------
class LiveRangeInfo {
const Function *const Meth; // Func for which live range info is held
LiveRangeMapType LiveRangeMap; // A map from Value * to LiveRange * to
// record all live ranges in a method
// created by constructLiveRanges
const TargetMachine& TM; // target machine description
std::vector<RegClass *> & RegClassList;// vector containing register classess
const MachineRegInfo& MRI; // machine reg info
CallRetInstrListType CallRetInstrList; // a list of all call/ret instrs
//------------ Private methods (see LiveRangeInfo.cpp for description)-------
void unionAndUpdateLRs(LiveRange *L1, LiveRange *L2);
void addInterference(const Instruction *Inst, const ValueSet *LVSet);
void suggestRegs4CallRets();
const Function *getMethod() { return Meth; }
public:
LiveRangeInfo(const Function *F,
const TargetMachine& tm,
std::vector<RegClass *> & RCList);
// Destructor to destroy all LiveRanges in the LiveRange Map
~LiveRangeInfo();
// Main entry point for live range construction
//
void constructLiveRanges();
// This method is used to add a live range created elsewhere (e.g.,
// in machine specific code) to the common live range map
//
inline void addLRToMap(const Value *Val, LiveRange *LR) {
assert(Val && LR && "Val/LR is NULL!\n");
assert((!LiveRangeMap[Val]) && "LR already set in map");
LiveRangeMap[Val] = LR;
}
// return the common live range map for this method
//
inline const LiveRangeMapType *const getLiveRangeMap() const
{ return &LiveRangeMap; }
// Method sed to get the corresponding live range of a Value
//
inline LiveRange *getLiveRangeForValue( const Value *const Val)
{ return LiveRangeMap[Val]; }
// Method used to get the Call and Return instruction list
//
inline CallRetInstrListType &getCallRetInstrList() {
return CallRetInstrList;
}
// Method for coalescing live ranges. Called only after interference info
// is calculated.
//
void coalesceLRs();
// debugging method to print the live ranges
//
void printLiveRanges();
};
#endif
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